This invention relates to optical scanning systems and more particularly to optical readers for bar coded labels located on the inside surface of a cylindrical tube.
Automatic reading of bar coded lebels located on the inner surfaces of cylindrical yarn tubes is necessary on many mechanized textile package handling systems. One example of an apparatus for scanning bar coded labels disposed on the inside surface of an open ended tube is disclosed by Herrin in U.S. Pat. No. 3,931,524. This apparatus must be moved into contact with the tube into reading relationship relative to the coded record. The movement of the apparatus into and out of engagement with the tube, if eliminated, could speed up the reading process and reduce the probability of scanning contamination by tube dust. Additionally, in practice it is probable that some labels will not be placed parallel to the tube edges and it would be desirable to scan at various angles inside the tube.